Thornwaldt cysts.

Thornwaldt cysts are rare and benign congenital cysts in the region of the pharyngeal bursa, formed by a communication between the notochord and the nasopharyngeal endoderm. They result from a mechanical obstruction, inflammation, or abscess of the pharyngeal bursa. They are superficial to the superior constrictor muscle and covered by the nasopharyngeal mucous membrane. Most cases are asymptomatic, and patients may rarely present symptoms such as nasal obstruction, foreign body sensation, hearing loss, and periodic halitosis. Therefore, they are often accidentally diagnosed on MRI. Asymptomatic cysts do not require treatment, whereas symptomatic cases require surgical intervention by endonasal or transoral approach. Marsupialization is the procedure of choice to avoid recurrences. The aim of this article is to present and discuss 2 cases of Thornwaldt cysts.